An Improved Maximum Power Point Tracking Algorithm with Current-Mode Control for Photovoltaic Applications

An improved perturb-and-observe maximum power point tracking algorithm is presented that incorporates a current compensated converter. In order to achieve fast response and accurate holding of the maximum photovoltaic (PV) power under changing environmental conditions, a variable perturbation step size is adopted. In addition, a control parameter α, is introduced to enhance the tracking sensitivity during abrupt changes of environmental conditions. Instead of directly perturbing the switch duty-cycle, the system operates on the current reference of an inner controller that regulates the PV current The effects of different values of fixed and variable step sizes are assessed through simulation and the results described. The performance of the new MPPT controller was simulated using the PLECS extension to Simulink.